Water Damaged MacBook Advice

Last year my niece spilled water on my 2015 MacBook Pro. Before it died it started acting crazy, the keys didn’t work properly (like double typing, typing the wrong key, not working at all), the mouse didn’t work, etc. Eventually it stopped working at all. I had someone look at it but they couldn’t fix it and my AppleCare was long expired. Anyway, it’s basically been shoved in a drawer for a year forgotten. Last week I came across it and I decided to sell it for spare parts. Out of interest, my mum plugged in my charger and lo and behold the dang thing boots up. But it’s not working super well. The keys are still acting crazy, the mouse will navigate but won’t click, and it won’t hold a charge. My question is: is it worth having someone look at it? Do you have any ideas on what could be done? TIA.